The present disclosure relates to a device that is capable of preventing an overcurrent from flowing into a wiring pattern or element disposed on a circuit board.
In recent years, there has been a high demand for downsizing the electronic circuit board, and in response to such demand, electronic components, and the like, have been downsized. However, the power to be handled by the electronic components, and the like, has not been extremely lowered with the downsizing thereof. Therefore, it can be the that the electronic components, and the like, have become easier to generate heat. However, some of the electronic components, and the like, cause malfunctioning, being overheated. Such malfunctioning, if caused, can have an adverse effect on the related parts, and the like, resulting in an unexpected accident. As one of the measures to prevent such an accident, there is available a method for protecting against an overcurrent to thereby suppress excessive heat from being generated.
Various methods of protecting against an overcurrent have been worked out. For example, there is available a method that monitors a voltage drop across a resistor connected in series. As another example, there is available a method that uses an element the resistance value of which is increased with an increase of the current passing therethrough, thereby an overcurrent being suppressed. However, any of the methods is faced with various problems. For example, there is presented a problem that a component for monitoring or suppressing the occurrence of an overcurrent occupies a large space. In addition, there is presented a problem that a great voltage drop is caused, or a long time is required to response to an overcurrent.